GRAND RAPIDS, Mich. (WOOD) — One of rock ‘n’ roll’s key pieces of memorabilia has been sold: Kurt Cobain’s favorite guitar.

The cobalt blue, left-handed 1969 Fender Mustang sold for approximately $4.5 million Sunday at Julien’s Auction, shattering the original estimate of $600,000. The buyer? Indianapolis Colts owner Jim Irsay.

It’s the same guitar Cobain used in the music video for “Smells Like Teen Spirit” and was used in recording hit records “Nevermind” and “In Utero.” Cobain played the guitar in certain live performances but not in shows where the band planned to destroy their instruments.

In a past interview with Guitar World, Cobain said the Mustang was his favorite guitar “in the whole world,” citing how hard it was to find reasonably priced, high-quality left-handed guitars.

Kurt Cobain called his 1969 Fender Mustang his favorite guitar ‘in the whole world.’ (Photo by ROBYN BECK/AFP via Getty Images)

Irsay has been outspoken about his support for mental health reform, recounting his battles with drug addiction. The Cobain family has agreed to donate a portion of the proceeds to the Colts’ Kicking The Stigma initiative, which gives away grants to Indiana-based mental health programs.

Irsay, an avid collector and rock ‘n’ roll fan, said Cobain’s story and his guitar are completely intertwined with mental health.

“Nevermind,” released in September 1991, catapulted Nirvana to international stardom, with Cobain front and center. Cobain, who was struggling with some health issues and drug addiction on top of the spotlight, took his own life in April 1994.

“This guitar is big, and it relates so much to stigma,” Irsay told The Indy Star. “When you have mental illness, people die. These are fatal diseases — bipolar, schizophrenia, post-partem depression, alcoholic addictions. With fatal diseases, people die, and they don’t choose to die. … Those of us who are alive, we’re not stronger or better. We didn’t get our act together more. We didn’t have more character. That’s where it’s so false.”

Julien’s Auctions has handled Cobain memorabilia in the past. In 2020, the auction house sold the rocker’s 1959 Martin acoustic-electric guitar that was used on Nirvana’s famous episode of “MTV Unplugged.” It fetched $6 million — making it the world’s most expensive guitar ever sold at auction. The cardigan Cobain wore for that performance sold for $334,000.

Irsay owns several rock ‘n’ roll collectibles, including dozens of musical instruments and one of Ringo Starr’s original Beatles drum kits.